BMC Complementary Medicine and Therapies (Jun 2024)

Kigelia africana fruit fractions inhibit in vitro alpha-glucosidase activity: a potential natural alpha-glucosidase inhibitor

  • Tumelo Akapelwa Muyenga,
  • Samuel K. Dominion Bamitale,
  • Dan Kibuule,
  • Simbarashe Sithole,
  • Stanley Mukanganyama,
  • Carlen Rudolph,
  • Luanne Venables,
  • Anna C. Hattingh,
  • Maryna van de Venter,
  • Christian Chinyere Ezeala

DOI
https://doi.org/10.1186/s12906-024-04510-5
Journal volume & issue
Vol. 24, no. 1
pp. 1 – 13

Abstract

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Abstract Background Diabetes affects 75% of people in low-income countries, where conventional drugs like metformin are available, but newer drugs like alpha-glucosidase inhibitors are not accessible to most Southern African patients. Aim To evaluate the α-glucosidase and α-amylase inhibitory activities of fractionated aqueous extracts of Kigelia africana fruit (KAFE) and their phytochemical fingerprints using gas chromatography-mass spectrometry (GC–MS). Materials and methods We studied K. africana fruit fractions' inhibitory effects on alpha-glucosidase and alpha-amylase using bioassay-guided fractionation, and analyzed their phytochemical profiles with GC–MS. Key findings Both the aqueous extract and ethyl acetate fraction of the aqueous extract exhibited a low dose-dependent inhibition of alpha-amylase activity (p < 0.0001). At a concentration of 500 μg/mL, the aqueous extract caused an alpha-glucosidase inhibition of 64.10 ± 2.7%, with an estimated IC50 of 193.7 μg/mL, while the ethyl acetate fraction had an inhibition of 89.82 ± 0.8% and an estimated IC50 of 10.41 μg/mL. The subfraction G, which had the highest alpha-glucosidase inhibitory activity at 85.10 ± 0.7%, had significantly lower activity than the ethyl acetate fraction. The most bioactive fraction was found to contain 11"(2-cyclopenten-1-yl) undecanoic acid, ( +)- and cyclopentane undecanoic acid as well as the indole alkaloids Akuammilan-17-ol-10-methoxy, N-nitroso-2-methyl-oxazolidine and epoxide Oxirane2.2″ -(1.4-butanediyl) bis-. Conclusion The K. africana fruit fraction demonstrated significant alpha-glucosidase inhibitory activity, while its alpha-amylase inhibitory activity was limited. This study suggests a potential natural alpha-glucosidase inhibitor and phytocompounds that could serve as leads for developing antidiabetic agents.

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